There is an urgent need to increase the number of veterinarian-scientists with expertise in infectious disease research. Over 60% of all infectious diseases of animals can also affect humans, and incidences of new, emerging zoonotic infectious diseases are increasing. Moreover there continues to be a threat of bioterrorism, with the risk of the deliberate introduction of pathogens into the U.S.food supply. A recent report by the National Research Council points out that there is an unprecedented decline in interest in public health and biomedical research by veterinarians, and argues that society's need to protect against these threats is outgrowing the veterinary knowledge base. Our program seeks to directly address this national need through our VMD-PhD training program in infectious disease-related research. This program is contained within the umbrella of our existing VMD-PhD program which has a 38 year track record of success. Our training program includes infectious disease-related programatic structures such as Infectious disease discussion groups, infectious disease-related seminars, the annual infectious-disease retreat, a global helath overview course, and externships at government public health agencies. This is coupled with infectious disease-related veterinary and graduate didactic education, rigorous biomedical PhD thesis research, and veterinary clinical training. The program is further supported by synergistic activities provided by the larger VMD-PhD and MD-PhD programs. Students receive VMD training at the Penn School of Veterinary Medicine, and PhD training within one of the Penn Biomedical Graduate Groups devoted to research in infectious disease-related research (1) Microbiology, Virology, and Parasitology,2) Immunology, or 3) Epidemiology and Biostatistics). This proposal brings together 43 faculty trainers with established research programs in the above disciplines. These faculty have a rich history of predoctoral and postdoctoral training and have trained nearly 700 individuals. Throughout the program, VMD and PhD curricula are interdigitated and programs are in place to bridge the two training programs to provide maximal synergy. Extensive oversight and advising systems are also in place to provide an efficient and well structured program. In summary, we seek to address a pressing national need for more veterinarian- scientists through our VMD-PhD program in infectious disease-related research.